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Deringoz Fatih Guliyev Vagif S. Nakai Eiichi Sawano Yoshihiro Shi Minglei 《Positivity》2019,23(3):727-757
Positivity - In the present paper, we will characterize the boundedness of the generalized fractional integral operators $$I_{\rho }$$ and the generalized fractional maximal operators $$M_{\rho }$$... 相似文献
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Yoshino Katsurayama Prof. Yasuhiro Ikabata Prof. Hajime Maeda Prof. Masahito Segi Prof. Hiromi Nakai Prof. Taniyuki Furuyama 《Chemistry (Weinheim an der Bergstrasse, Germany)》2022,28(2):e202103223
The high penetration of near-infrared (NIR) light makes it effective for use in selective reactions under light-shielded conditions, such as in sealed reactors and deep tissues. Herein, we report the development of phthalocyanine catalysts directly activated by NIR light to transform small organic molecules. The desired photocatalytic properties were achieved in the phthalocyanines by introducing the appropriate peripheral substituents and central metal. These phthalocyanine photocatalysts promote cross-dehydrogenative-coupling (CDC) under irradiation with 810 nm NIR light. The choice of solvent is important, and a mixture of a reaction-accelerating (pyridine) and -decelerating (methanol) solvents was particularly effective. Moreover, we demonstrate photoreactions under visible-light-shielded conditions through the transmission of NIR light. A combined experimental and computational mechanistic analysis revealed that this NIR reaction does not involve a photoredox-type mechanism with electron transfer, but instead a singlet-oxygen-mediated mechanism with energy transfer. 相似文献
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The extrapolation scheme of correlation energy is revisited to evaluate the complete basis set limit from double‐zeta (DZ) and triple‐zeta levels of calculations. The DZ level results are adjusted to the standard asymptotic behavior with respect to the cardinal number, observed at the higher levels of basis sets. Two types of adjusting schemes with effective scaling factors, which recover errors in extrapolations with the DZ level basis set, are examined. The first scheme scales the cardinal number for the DZ level energy, while the second scheme scales the prefactor of the extrapolation function. Systematic assessments on the Gaussian‐3X and Gaussian‐2 test sets reveal that these calibration schemes successfully and drastically reduce errors without additional computational efforts. © 2015 Wiley Periodicals, Inc. 相似文献
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Kyosuke Doi Yuki Yamada Masaki Okoshi Junichi Ono Chien‐Pin Chou Hiromi Nakai Atsuo Yamada 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(24):8108-8112
Alkaline metals are an ideal negative electrode for rechargeable batteries. Forming a fluorine‐rich interphase by a fluorinated electrolyte is recognized as key to utilizing lithium metal electrodes, and the same strategy is being applied to sodium metal electrodes. However, their reversible plating/stripping reactions have yet to be achieved. Herein, we report a contrary concept of fluorine‐free electrolytes for sodium metal batteries. A sodium tetraphenylborate/monoglyme electrolyte enables reversible sodium plating/stripping at an average Coulombic efficiency of 99.85 % over 300 cycles. Importantly, the interphase is composed mainly of carbon, oxygen, and sodium elements with a negligible presence of fluorine, but it has both high stability and extremely low resistance. This work suggests a new direction for stabilizing sodium metal electrodes via fluorine‐free interphases. 相似文献
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Kazuaki Kuwata Masashi SuzukiYoshikazu Inami Kengo HanayaTakeshi Sugai Mitsuru Shoji 《Tetrahedron letters》2014
A stereoselective synthesis of scyphostatin hydrophilic moiety was accomplished. Substrate- and reagent-controlled dihydroxylation of tri- and monosubstituted alkenes afforded desired diols, respectively. Chemo- and stereoselective allylation of α-(methoxycarbonyl)cyclohexanone provided allylcyclohexanol. Oxidative cleavage of glycol and subsequent β-elimination of siloxycyclohexanone furnished the desired epoxycyclohexenone. 相似文献
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Natural products often possess various spin systems consisting of a methine group directly bonded to a methyl group (e.g. –CHa–CHb(CH3)–CHc–). The methine proton Hb splits into a broadened multiplet by coupling with several vicinal protons, rendering analysis difficult of nJC–H with respect to Hb in the J‐resolved HMBC‐1. In purpose of the reliable and easy measurements of nJC–H and nJH–H in the aforesaid spin system, we have developed a new technique, named BASHD‐J‐resolved‐HMBC. This method incorporates band selective homo decoupled pulse and J‐scaling pulse into HMBC. In this method, high resolution cross peaks can be observed along the F1 axis by J‐scaling pulse, and band selective homo decoupled pulse simplified multiplet signals. Determinations of nJC–H and nJH–H of multiplet signals can easily be performed using the proposed pulse sequence. Copyright © 2013 John Wiley & Sons, Ltd. 相似文献
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Motohiro Aiba Takahiro Tokuyama Susumu Baba Hidetoshi Matsumoto Hiroki Tomioka Tomoya Higashihara Mitsuru Ueda 《Journal of polymer science. Part A, Polymer chemistry》2014,52(9):1275-1281
A new concept for the method to provide semipermeability in ultrathin and single‐component wholly aromatic polyamide membranes has been developed for the first time. It was found that water molecules could permeate through the membrane prepared not from polyamides containing flexible ether, bulky binaphthyl, or fluorene rigid units, but one with carboxylic acid groups under a reverse osmosis mode. However, the enhancement of water transport properties by introducing the hydrophilic group of polyamide was not substantial. Therefore, polyamide membranes were prepared from the solution containing aqueous additives in order to weaken hydrogen bonds between polymer chains and thereby to suppress the aggregation of the polymer chains. As a result, water flux was dramatically improved with slightly improved NaCl rejection. Our analyses based on attenuated total reflectance Fourier transform infrared spectroscopy and solid‐state carbon polarization and magic angle spinning nuclear magnetic resonance (13C CPMAS NMR) spectroscopy confirmed that the aggregation of polymer chains due to the hydrogen bonds among the amide linkages was suppressed by the co‐ordination of the aqueous additives to the amide linkage. The state of water in the membranes analyzed by differential scanning calorimetry also supported the formation of pores. © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2014 , 52, 1275–1281 相似文献
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